As mobile networks rapidly evolve, it is widely forecast that there will be a profusion of connected devices and associated cells. In addition to conventional macro cells, many “small cells” will work at low energy levels and are designed to communicate with devices in the immediate local area. In this document small cell are defined as any radio cell with much smaller coverage area than conventional “macro” cells, including public “pico cells”, residential femto cells, or Wifi access points.
A current example of a small cell is a femto-cell. A femto-cell is a portable, consumer deployed unit typically using licensed spectrum. Unlike the traditional base station, backhaul to the wireless communications network is via a consumer provided packet data (IP) connection, e.g. a DSL connection, rather than the dedicated or leased line switched circuit backhaul used in first and second generation cellular systems. Designed for indoor coverage, femto-cell radio power output nominally ranges from 0.5 to 1 Watt. Femto-cells are also known as “Home eNodeB's” in the Third Generation Partnership Program's (3GPP) Long Term Evolution (LTE) or Evolved UTRAN (eUTRAN) program
Using small cells as a low cost approach to adding coverage and capacity to the wireless communications network raises some difficulties that embodiments of the present invention seek to address. The placement of small, inexpensive radio cells is not usually practicable by conventional cell location planning methods. Location of the small-cell is of the upmost importance however, since the small-cell location may be the only connection available to mobile users who have specific data needs (high bandwidth, low latency etc.) or who are located in buildings which create challenging reception conditions between the user and other network cells. Incorrect location can have a critical effect on the performance of the wider network (e.g. in terms of interference), and this is the key issue to be addressed for successful deployment.
Due to the number of cell types which are likely to be used in future mobile communication networks, which have different capacities, support different network topologies and have different bandwidth capabilities and the diversity of application needs, there is however an advantage to be gained in assisting the placement of small cells such that it optimally meets network needs, and also optimally meets user needs in the context of their location dependant usage of network resources.
More information can be found at “US2010120394 (A1)—Femto-Cell Location by Proxy Methods”
Current cell location planning methods are in general not suitable for the guided placement of small cells (whose placement may be undertaken by the network operator or the consumers), and other placement methods which have been discovered in the prior-art do not consider the contextual nature of a users mobile device use. Accordingly, at present there is no placement method or apparatus which allows the consumer placement of small cells in a way which takes into account the location specific needs of applications.
Specific restrictions include:    (i) The placement of the small cell should be consistent with the context in which users are utilising the network and the network resources available from other adjacent cells. For example, a user may need a very high bandwidth low latency connection in a specific location. A high bandwidth low latency connection may only be available in one part of the building (which has good coverage from a new macro cell) but the other part of the building (which only has coverage from previous generation cells) may coincide with the users normal location—which results in a limitation on the efficiency of associated applications. Clearly in this instance the small cell should be placed so as to meet the contextual location specific needs of the user, which is the subject of this invention. In other words, the position of the cell has to take into account both the existing coverage and the user's position-dependent requirements, which are independent of each other. Thus, depending on the user's needs, the small cell might coincide with the area of poor coverage, or it might coincide with the area of available good coverage (but for example low capacity of the macro cellular network), if this where it is required by the user(s).    (ii) While cell location planning or participatory sensing methods may identify areas of low or strong signal strength from surrounding cells, known approaches do not take into account how objects, such as stone walls, attenuate signals across a range of frequencies in the context of an applications needs. This is likely to become increasingly important for advanced mobile communication networks due to the deployment of communication links operating at different frequencies, ranging from GHz through THz, which may be omni- or unidirectional (if adaptive beamforming is used for example). If this is not considered in the placement of a small cell then suboptimal links may result as its placement will not adequately reflect the location and location specific signal attenuation of other cells in the area.
US2010120394 (A1)—Femto-Cell Location by Proxy Methods
Location of small, consumer deployed femto-cells cannot be determined by the usual site survey methods. Location of attached mobiles allows for a proxy location of the femto-cell that can then be used for wireless network planning including the provisioning of a calculated default emergency services location for the femto-cell.
The document discloses a method for use by a wireless location system (WLS) in locating a femto-cell device operating in a wireless communications system, comprising:    discovering and initiating location of the femto-cell device;    determining an identification of a mobile station (MS) being served by the femto-cell device;    determining the location of the MS; and    determining the location of the femto-cell device using the location of the MS.
Consequently a determination of the location of consumer deployed femto-cell using a proxy method based on the location of a Mobile Station is disclosed.
US2008151777 (A1)—System and Method for Core Network Topology Router Placement Planning
Systems and methods for core network topology router placement planning are provided. The systems and methods may use existing network data to create a data set and use the data set to optimize a network for the placement of routers.
1. A method, comprising:    identifying a network topology;    calculating circuit locations from the network topology;    creating a dataset from the network topology and the circuit locations; and    solving the dataset to determine at least one output indicative of a proposed placement of one or more routers in the network topology.
Summary: uses network topology to calculate placement location
US2008279552 (A1)—Methods of Placing Reconfigurable Optical Add/Drop Multiplexers (ROADMS) in a Network
A distributed network including at least two Reconfigurable Optical Add/Drop Multiplexers (ROADMs) may be designed by a method including simulating routing of data traffic in a distributed network. The method may also include identifying a first location for placement of a first ROADM based at least partially on the simulated routing of the data traffic. The method may also include simulating rerouting of data traffic in the distributed network including the first ROADM at the first location. The method may further include identifying a second location for placement of a second ROADM based at least partially on the simulated rerouting of the data traffic.
The document discloses a method, comprising:    identifying a plurality of candidate locations based at least partially on an initial simulated routing of data traffic in a distributed network;    selecting at least one of the plurality of candidate locations for placement of a Reconfigurable Optical Add/Drop Multiplexer (ROADM) based at least partially on a cost; and    simulating rerouting of data traffic in the distributed network including the at least one ROADM at the at least one selected candidate location.
The document uses simulations of routing data to assist in placement of multiplexers.
WO02071781 (A1)—Method of Cell Site Location in a Cellular Mobile Network
The location of a fixed transmit cell site in a cellular mobile telephone network is identified by a method including the steps of: deriving survey data measurements of the network by means of a mobile test telephone; grouping into individual subsets the survey data measurements derived on a drive route; identifying first site cluster data and second site cluster data for the transmit cell site location by means of multiple triangulation computations in which each individual point in respect of the geographical location data of the receiver of the test telephone is paired with each other individual point to provide in each case a pair of locations whose distance from the transmit cell site location is determined from the corresponding timing advance data; and determining which of the first site and second site cluster data has the greatest cluster density and determining centre of gravity of that site as identifying the location of the fixed transmit cell site. The survey data measurements comprise geographical location data of a receiver of the test telephone; timing advance data providing distance between the fixed transmit cell site and the receiver of the test telephone; and cell identity field data. Each subset of survey data measurements corresponds to measurements belonging to the same fixed transmit cell site.
The document discloses a method for identifying the location of a fixed transmit cell site in a cellular mobile telephone network, comprising the steps of: deriving survey data measurements of the network by means of a mobile test telephone, the survey data measurements comprising: geographical location data of a receiver of the test telephone; timing advance data providing distance between the fixed transmit cell site and the receiver of the test telephone; and cell identity field data; grouping into individual subsets the survey data measurements derived on a drive route, wherein each subset corresponds to measurements belonging to the same fixed transmit cell site; identifying first site cluster data and second site cluster data for the transmit cell site location by means of multiple triangulation computations in which each individual point in respect of the geographical location data of the receiver of the test telephone is paired with each other individual point to provide in each case a pair of locations whose distance from the transmit cell site location is determined from the corresponding timing advance data; and determining which of the first site and second site cluster data has the greatest cluster density and determining centre of gravity of that site as identifying the location of the fixed transmit cell site.
The document uses site survey data as part of a method to locate cells within a cellular network
US2010309790 (A1)—Femto Base Stations and Methods Operating the Same
Femto base stations and methods described herein suppress the need for an external GPS antenna and cable, while still providing a network service provider with the ability to obtain the desired GPS location coordinates and the user with the flexibility of placing the femto cell at the location of their choice within a home regardless of GPS signal strength.
The US application comprise a method operating a femto base station in a wireless network, the method comprising: deciding, at the femto base station, whether position information signals are available;    determining, at the femto base station, whether anchor position information stored in a memory at the femto base station is valid if the deciding step decides that position information signals are unavailable, the anchor position information being indicative of an anchor position of the femto base station; and    identifying network configuration parameters for the femto base station if the determining step determines that the stored anchor position information is valid.